Air conditioning apparatuses

ABSTRACT

A reversible air conditioner having a casing divided in a warm and in a cold section by a partition wall, a motor supported in said wall, partly extending in one and partly in the other of said sections and having a shaft projecting from either its ends, a fan in each section for promoting air circulation in each section, said fans being of combined inlet axial and delivery tangential flow type, having recesses oppositely to their axial inlets, and being arranged back-to-back in said sections about the opposite ends of said motor shaft, and the said motor being substantially compenetrated in said recesses of fans.

United States Patent Riello June 13, 1972 [54] AIR CONDITIONING APPARATUSES 2,-40L206 5/l946 Van Rifswijk ..46/l86 2,472,792 6/l949 Cohler ...62/262 [72] Inventor. Vaierio Giordano Riello, Legnago, Italy 2,942.43) 6H9) wuesthoff H 62/262 [73] Assignees Rielio Condizionatori S.A.S. di Giordano 2, 45,362 7/1960 Gould 62/262 Riello & C., Bevilacqua, Verona, Italy 3,298,444 1/1967 Haas t. 4l6/i86 Filed. g 4 1970 3,406,530 l0/l968 Riello ..62/262 [2 l] App]. No.: 60,902 Primary Examiner-William J, Wye

Attorney-Michael S. Striker [30] Foreign Application Priority Data 57] ABSTRACT 1969 "2067] A reversible air conditioner having a casing divided in a warm and in a cold section by a partition wall. a motor supported in 3551; said wall, partly extending in one and partly in the other of [58] Fie'ld 416/186 said sections and having a shaft projecting from either its ends.

a fan in each section for promoting air circulation in each sec- [56] References Cited tion. said fans being of combined inlet axial and delivery tangential flow type. having recesses oppositely to their axial in- UNITED STATES PATENTS lets, and being arranged back-to-back in said sections about the o posite ends of said motor shaft, and the said motor bein P 8 2g t D d substantially compenetrated in said recesses of fans. avl son. 2.054, I 44 9/1936 Swigert ..4l6/l86 11 Claims, 9 Drawing Fi ures ooooooooooofooo 61 F5 53 o o t )L .62 o O 3 73 o 'i o l o 1 71 0 o 72 of; 24 l O I 3 '1 0 LL 0 70 L o PATENTEDJun 13 1912 3. 668 887 SHEET 2 or 3 INVENTOR Mae/2:0 6'10WPIRA BY all? ATTORNEY PATENTEDJUH 1 3 1972 saw 3 OF 3 I NVENTOR in mm 6/094 Flaw ATTORNEY AIR CONDITIONING APPARATUSES BACKGROUND OF THE INVENTION This invention concerns improvements in and to air conditioning apparatuses and devices adapted for cooling and simultaneous dehumidification and possibly for heating and simultaneous humidification of the air which is then fed to closed rooms. The improvements according to the invention concern in particular air conditioning devices of relatively small size and designed for the control of humidity and temperature of air in single rooms, or possibly in a few rooms totalling a rather small volume, being such as the devices known on trade under the Italian Registered Trade Mark Rotoclima," i.e., devices which position can be reversed by having them turned through 180", whereby same apparatus can be quickly and readily adapted by the same user either for cooling and for heating of rooms, such as in spring or autumn time, when the regular heating plant is not in operation, or is insufficiently operating.

The invention has also for its object the air conditioners embodying said improvements and characterized by the features, properties and advantages hereinbelow set forth.

Such air conditioners are well known and widely in use. They usually comprise a case, having both front and rear sides formed with opening pairs of inlet and outlet openings, each pair being in communication with the room inside and the room outside, respectively. Connected with said pairs of openings are separate spaces formed inside of said case, and wherein fans or like means, driven by one or more electric motors are fitted, said spaces being provided with passages or channels designed to form therein two separate circuits that are run through by the air coming from the room to be conditioned, and by the air drawn from the outer atmosphere and that is sent back again thereto, respectively. The flows running along said circuits are compelled to pass through heat exchangers formed by the evaporator and by the condenser, respectively, of a conventionally operating refrigerating unit, enclosed within the case to remove heat from one of the air flows and to transfer same to the other flow. For cooling the air of a conditioned room, the evaporator is obviously located on the side of openings directed toward the inside of space to be conditioned.

One of requirements which are to be preferably (though not necessarily) met by the considered air conditioners, is the compactness, i.e., the reduced sizes thereof. In particular, that portion of air conditioner that extends from the window or wall through which the communication with the outer atmosphere is established, should be as small as possible.

Another and most significant technical requirement which is to be met is that concerning the degree at which advantage is taken of the available refrigerating capacity, and which is to be as high as possible, by a highly efficient exchange of heat. Such condition requires therefore the best utilization of heat exchange surfaces, and the best efficiency of the surface area of the grid formed by each heat exchanger, and it can be attained only when all points of said area are crossed by air threads flowing at the highest possible speed consistent with safe and proper service.

Further desirable requirements are a noiseless running and that no powerful blasts of air be directed into the room to be conditioned, thus preventing unpleasant concentrations or localizations of cold, or possibly hot air inside of same room. Thisimplies therefore that the grid directed to room inside he crossed by an uniform and relatively slow blast of air. In addition, in reversible" air conditioners, the above requirements are to be met by both heat input and heat output section of same conditioners.

Finally, it is desirable that such air conditioners have a simple structure and preferably comprise a single motor for driving both fans, in the "cold and "warm" sections, respectively, inside of same air conditioner.

Generally, there is provided an electric motor having a shaft projecting from either ends thereof, and by which said two fans, keyed onto the ends of projecting portions of said shaft are driven.

The air conditioners of such type comprise a basically parallelepipedon shaped casing, which major vertical opposite sides are formed with openings arranged in pairs, and which inside is subdivided into two approximately equal chambers by a diaphragm lying in a plane parallel to said sides, acting said chambers as the warm" section, and as the "cold" sections, respectively, of air conditioner. The length or depth of said sections, when measured in a direction orthogonal to same sides, should be as small as possible-at any rate not greater than a few decimeters, since the horizontal dimension of the apparatusin the meaning of projection thereof inside of roomis defined by the sum of said depths. Taking into account that a part of such depths is taken-up by the heat exchangers (evaporator and condenser, respectively) and by the required structural components (grids, filters and so on), a rather little space is left for the intake of air through at least a part of related heat exchanger and the reversal for l of draft, in order to bring the air back into same room wherefrom it was drawn. in complying with the above conditions, heavy technical problems are encountered, above all in the design, positioning and operation of fans, as well as of pipe connections, conveyor ducts, guide and deflection means of draft.

As well known, use may be made of two different types of fans (meaning by the term fans rotary mechanical means designed to generate and to maintain a draft inside of respective chambers), and precisely the axial-flow fans (practically helical or screw fans), and radial-flow fans with tangential outlets (practically centrifugal fans or blowers, which usually are drum-shaped). Said two types of fans show each their own advantages and disadvantages. A uniform sucking action, which is in addition properly distributed in a very wide intake cone is exerted by the axial-flow, or helical fans; however, they require a wide space downstream of them for the deflection through 180 of the draft, which in addition should preferably be concentrated on a portion only of the grid or opening through which the air is drawn or impelled back into the room, being also said portion, above all in the warm" section, taken-up preferably by a part of the condenser.

In the centrifugal-flow fans, a first deflection through is directly imparted to the draft which is axially sucked, and then impelled in the rotation plane of same fans. However, the axial sucking results in a very concentrated input draft, because by the centrifugal fan a vortex is practically generated wherein the maximum vacuum occurs in the axis thereof. Therefore, when such fans are placed very near to a heat exchanger, the useful crossing path thereof is utilized in a very incomplete and improper degree only.

The silentness of running is substantially inversely proportional to angular speed of fan wheels, and in particular to peripheral speed of leading edges of the fan paddles. The delivery, for each given angular speed, is on turn approximately proportional to wheel diameter, and to the whole of wheel sectional area which is traversed by the air. Thus, from a theoretical viewpoint, large diameter wheels would be preferred, running at a low RPM, which on turn require large paddles, with consequent increase in the linear length of their leading edges, across which the undesirable sound vibrations are generated at a frequency that increases with increasing peripheral speed of said leading edges.

What stated above is deemed sufficient to recognize that though the considered air conditioners, and in particular those of reversible type, may appear, at a glance, very simple and easily designable mechanisms, they however require the solution of many and rather hard technical problems, in particular of aerodynamic nature, if a satisfactory compromise is to be attained between the conflicting requirements of highly efficient heat exchange, silent running, small sizes, uniform flowing at a relatively low speed of drafts generated in the conditioned room, in addition to requirements concerned with a satisfying simplicity of construction, assembling and possible overhauling and servicing.

SUMMARY According to the invention, it has been ascertained that such compromise can be attained and other problems can be satisfactorily solved by providing, as mechanical means by which the drafts are generated and maintained in both sections of air conditioners, axial and radial flow fans, each having an essentially axial intake and an essentially tangential delivery, and having paddles the leading edges of which are caused to run, at any of their points, at a peripheral speed lower than that of their trailing edges. Wheels with paddles having spirally bent leading edges are preferably used. Moreover the pitch of paddle portions adjacent to their lead ing edges is preferably essentially constant, whereby to impart also essentially equal linear speeds in all points of circular zone as defined by said leading edges, to air particles that are acted upon by the paddles, thus obtaining a uniform suction in all points of a wide intake cone.

Further, said fan wheels comprise paddles which are supported and clamped between surfaces that are concave shaped on the paddle outside, and convex shaped on the paddle inside, thus defining therebetween an annular channel which circular inlet section is essentially plane, while the outlet section is nearly cylindrically shaped, whereby a first deflection through nearly 90 is imparted to air that flows between same surfaces.

Thus, the advantageous properties of axial-flow fans (proper, uniform and conveniently distributed intake) and of tangential delivery of draft in a plane essentially normal to rotation axis (which draft can be then easily collected, conveyed, made more uniform and possibly decelerated in a spiral conveyor, and finally again deflected to the outside), are combined with those of silent running, due to low peripheral speed of leading edges, and of large delivery that can be attained even at low RPM, owing to the larger diameter of wheel at the trailing edges thereof.

Moreover, the particular orientation of blades of these combined axial intake and radial delivery fans results in a tridimensional configuration of the wheel, which comprises a marked concavity on its side opposite to inlet side. Advantage is taken from such concavity to accomodate the most part of electric motor within the wheel body. Thus, according to an important feature of the invention, the wheels are fitted back to back at either ends of electric motor shaft, being the total axial length of assembly thus formed much smaller than the sum of single axial lengths of wheels and motor. Moreover, considering that the first deflection through 90 of induced drafts is performed within same wheels, the combination of said features practically allows to restrict the depth of sections wherein the intake, the deflection through I80 and the delivery of air are performed, to a value close to axial dimensions of same fan wheel. Consequently, the total dimension of the improved air conditioner, as measured between their vertical sides that are directed to the outside and to the inside of room, respectivelydue account being taken of the wide intake cone of wheels-can be restricted to a value slightly larger than the sum of thicknesses of heat exchangers (evaporator and condenser), and of axial lengths of the two wheels, between which the electric motor is practically enclosed and supported by the structural wall acting as a partition diaphragm between the warm and cold sections of air conditioner. Consequently, the improved air conditioner according to the invention, is characterized in that it comprises, within an essentially parallelepipedon shaped casing, having two major vertical opposite sides, either of which can be associated and engaged with a pipe union, having an inlet or passage adapted to be installed in an orifice or opening as formed in a window pane or other partition wall between the room to be conditioned and the outside, and with a shielding grid adapted to be directed toward the inside of said room: two warm" and "cold zones, respectively, that are separed by a diaphragm, essentially parallel to said vertical sides and approximately equidistant therefrom; an electric motor horizontally fitted in said diaphragm in such a manner as to extend symmetrically itself from either sides thereof, and with a shaft projecting out of both of their ends; two combined axialcentrifugal flow wheels, each having a back recess at their sides opposite to their axial inlets, and fitted back to back on either shaft ends in the cold zone and warm zone, respectively, being the adjacent half of said motor at least partly accomodated within said back recess; deflector means by which the drafts generated by said wheels are deflected through ab. to the outside, and a refrigerating unit comprising a plategrid type evaporator and an also plate-grid type condenser, fitted in front of wheel axial inlets and close to the adjacent vertical side by which the warm, and respectively the cold sections are terminated, being the sum of axial dimensions of said wheels and of said motor smaller than the distance between the planes as defined by said inlet openings of wheels.

The above and further, more specific features of the invention will be better understood from a consideration of the following detailed description of a preferred embodiment of the invention, taken with the accompanying drawings, being both description and drawings given as a not restrictive example only.

DRAWINGS FIG. I is a plan simplified view of the improved air conditioner shown in a section taken on the horizontal plane I--I in FIG. 2.

FIG. 2 is a vertical sectional view of same conditioner, taken on the plane II-ll in FIG. I, wherein the axis of wheels is also contained.

FIG. 3 is a side elevational view of the inside of the air conditioner shown in FIG. 1, and

FIG. 4 is a diagrammatic diametral section of one of wheels.

FIGS. 4A, 4B and 4C are enlarged sections of a wheel paddle taken on the planes lVa-lVa, lVb-IVb and IVc-IVc, respectively, in FIG. 4.

FIG. 5 shows the reversible components of air conditioner, in a position reversed in respect of operating position as shown in FIG. 2, and

FIG. 6 is an exploded sectional view of the main components of the air conditioner.

PREFERRED EMBODIMENT As shown in FIGS. 1 to 3 inclusive, the air conditioner basically consists, on its whole, of a parallelepipedon shaped casing, having two major opposite sides, and subdivided into two approximately symmetric portions by a middle vertical diaphragm I0, parallel to said major sides, and by which two sections are defined inside of said casing. Such sections may be appropriately called, on the basis of their function, by the terms cold section I4 and warm section 12.

The side wall perpendicular to diaphragm 10 of said sections, are spiral shaped, as clearly shown in FIG. 3, to serve as delivery conveyors for the fan wheels (as described later on), having said conveyors their outlets in upper spaces 16 and 18 respectively, which as clearly shown in FIG. 2, are shaped in such a manner as to deflect through 90 to the outside, the air blasts delivered by the wheels into said conveyors.

The side walls 20 and 22 respectively of said parallelepipedon casing are formed with circular openings 24 and 26 respectively, juxtaposed to wheel axial inlets. Fitted in said diaphragm I0 is an electric motor 28 having preferably a relatively low rating (e.g., a six-pole asynchronous motor) and extending in part into one and in part into the other of said sections. The two wheels are keyed on and driven by the shaft of said motor, which extends out of both ends thereof.

Outside of and close to said walls 20, 22 the heat exchangers are fitted. Such exchangers consist of condenser 30 and evaporator 32 of refrigerating unit, which refrigeration compressor 34 already per se known is fitted in a recess 36 of air conditioner casing, sidewise to said warm and cold sections. Such heat exchangers are of the already well known flat design and are fitted parallel and close to said walls 20, 22. Said condenser 30 preferably extends also in front of space 16 to be thereby crossed in part by the induced draught and in part by the delivered blast.

The two fan wheels, indicated generally by the reference numerals 38 and 40 are of properly diversified sizes, to obtain the required proportionality between the flow rates of air blasts that are impelled through the condenser and the evaporator, respectively, and their distinctive diametral sections are shown in FIG. 2, while their operating features are outlined in FIGS. 4 4C (wherein the wheel 40 only is exemplified, which description therefore holds also for the exactly corresponding-apart from the larger sizeswheel 38).

As shown in FIGS. 3 and 4, said wheels are preferably titted with paddle rims 42, which paddles are clamped between an inwardly convex annular front member 44 having an inside diameter smaller than the outer diameter, and a centrally flattened back member 46 having an inwardly concave perimetral portion, thereby forming on the back a recess wherein a substantial part of axial dimension of frame of motor 28 is accomodated. Consequently, the spacing between the wheel backs is remarkably smaller than the axial dimension of motor, as shown in particular in FIG. 2, while the interval between the planes as defined by the intake orifices 24, 26 is much smaller than the sum of axial dimensions of motor 28 and of the two wheels 38 and 40.

The outside diameter of back portion 46 is only slightly smaller than the outer diameter of fore annular portion 44, while the inside diameter of concave perimetral rim of said back portion 46 is smaller than the inside diameter of said annular front portion 44. Moreover, the width of annular channel as defined by said portions 44, 46 is preferably gradually decreasing toward the outside, being same channel also bent, whereby to deflect the air blast from the axial direction of inlet, to a plane orthogonal to wheel axes.

In particular, the outlet portion or trailing edge 48 of each of wheel paddles extends between the outer borders of said two portions 44, 46, while the preferably convex leading edge extends between the inner contours of said portion 44 and of concave rim of back portion 46. Moreover the paddles are bent so that a spiral lead is formed by their intake portions or leading edges 50 in respect of wheel axes, while their trailing edges 48 are essentially parallel to same axes. For the combination of such bendings with the orientation ofleading edge 50, this latter shows and angle of incidence a and B, 7 respectively which gradually increases proportionally to decreasing of radial value a and b, c respectively of their points, as clearly shown by a comparison of FIGS. 4A 4C.

Consequently, said wheels practically act as axial-flow fans having an essentially constant pitch on their intake side, and as centrifugal fans on their delivery side, thereby imposing the required deflection through 90 to the air blast that flows along said annular channel, in the zone wherein said air blast is acted upon by the dynamic action as exerted by the paddles.

Moreover, to prevent the phenomena ofa too high localized compression of air, both wheels are preferably fitted with a pretty large number of paddles, as shown in FIG. 3, in order that the peripheral spacing of trailing edges 48 of adjacent paddles be preferably not greater than the axial dimension of same edge.

The use of wheels of the above described or equivalent type allows to obtain an advantageous combination of effects, as previously stated, and in particular:

use can be made of wheels having a rather large diameter without increasing the overall sizes, and in particular the axial dimension of rotary assembly, thereby ensuring large flow rates at advantageously low RPM. As an example, by the use of a wheel 38 of outer diameter of 250 mms about, and a wheel 40 of outer diameter of 230 mms about, driven at ab. 900 RPM by a fractional motor (with a rating of 50 watts), flow rates of about 450 cum/hr and of 350 cum/hr, respectively can be easily attained, being said flow rates largely suffcient for proper operation of a unit with a rating of L200 watts about, thus obtaining, on the whole, a heat exchange of an order of magnitude of 2,000 refrigerating units/he, all with inlet and outlet air blasts having sharply differentiated speeds, as stated later on.

The above advantages add themselves to the afore stated advantageous possibility of the realization of a very "flat" air conditioner as shown in particular by the FIG. 6. As a mere example, it may reasonably be assumed that the axial dimension D of motor 28 is about mms, while the axial dimensions of the two wheels 38, 40 are of mms and 80 mms respectively. The sum of said axial dimensions would therefore amount to 250 mms. However, since the motor is accomodated into axial back recesses of both wheels, the total axial dimension lc (see FIG. 5) can be reduced down to about 200 mms and less and thus to a value much smaller than that ofsaid sum.

While keeping the dimensions of warm and cold sections, measured parallely to wheel axes, within very narrow limits (according to above stated exemplifying values: dimensions of an order of magnitude of [30 and I20 mms, respectively), the drafts are deflected through 90 by at least three times (between the axial inlet and the tangential outlet of wheels, then upwardly along the spiral or scroll shaped conveyors and finally to the outside in the conveying components 16, 18 under very gradual and uniform conditions, without substantial perturbation and whirling phenomena, to great advantage of a high aerodynamic efficiency as well as of silent running.

Owing to the inherent properties of axial-flow fans, to which the wheels 38, 40 correspond in their inlet portions, and in particular of fans having spirally bent paddles, the induced draft occurs the form of a very wide cone as diagrammatically shown in FIG. 4 by a plurality of small arrows.

The operation of said wheels can be additionally pre-set in such a manner as to obtain a sharp differentiation between the inlet and the outlet speeds of air blasts. As a matter of fact, the inlet sides of same wheels may be compared to airscrews having a diameter equal to that of annular portions 44 thereof, and which pitch is established by the angle of incidence of their leading edges 50, as previously outlined. Thus, each given RPM is obviously associated with a given flow rate and a given linear speed of air threads on the inlet side, which speed is reduced already at a small distance from the inlet openings of wheels, owing to the width of induction cone. The annular outlet of wheel can be pre-set in such a manner as to show a free area much smaller than that of circular inlet opening. The paddles therefore, at their trailing edges act as centrifugating blades.

Taking into account the diameter at the trailing edge 48, for any rotational speed a linear speed much higher than that at the inlet side can be imparted to air threads at the outlet side of wheel. It can be observed that such acceleration is not caused merely by a throttling of cross section of passage (with consequent pressure loss and perturbations in the draft) but by a proper dynamic action, that is continuously exerted by the blades 42 from the inlet, to the outlet side of wheel.

Said acceleration also allows to obtain a further important advantage, which will be dealt with in more detail later on, ensuing from said differentiation in the speeds, without any head loss and therefore with a high aerodynamic efficiency, due account being taken, in particular, of the not negligible resistances that are encountered by the air blast in the passages through the heat exchangers, the grids, the filters and at any rate in the whole travel inside of the air conditioner.

The structural and operating components which have been previously described both individually and as a whole, will form the proper air conditioner, which is capable to absorb heat on one of its sides, and specifically on the evaporator side 32 and to give it back into the (outer or inner) surrounding at the condenser side 30.

In order to obtain the required reversibility of air conditioner operation, its opposite sides, that are formed with the inlet and the outlet ports for the air blast that is impelled to pass through the warm and cold sections, are alternately associated with components 60, 61 respectively, by which a communication is established between said sections and the room to be conditioned, and the outer environment, respectively. Obviously. to establish said communication, said components shall show widely different structural features. In particular, the component 60 which is directed toward the room to be conditioned, is to be fitted with suitably oriented and distributed grids, thus forming a panel by which the air conditioner is aesthetically completed. Conversely, the component 61 is to be formed with an opening 62 that, to facilitate the operations of preparation and installation, is preferably-but not necessarily-circular shaped, and that is designed to be inserted through a window pane 63 or the like.

As shown in FIGS. 1, 2 and 5, said components comprise an essentially box-like structure, generally indicated by 64 and 65 respectively, and having equal sizes and configuration, in order to be indifferently associated with either opposite vertical sides of air conditioner. Obviously, to reverse the operating conditions of same conditioner, since the component 61 by which a communication with the outside is established must be left in place, the proper conditioner shall be turned through 180 about a vertical axis, or at any rate about an axis parallel to window pane 63 or other partition wall by which the room is separed from the outside. From a comparison of FIGS. 2 and 5, the reversal of air conditioner in respect of components 60, 6] which are left in place, is manifest.

The component 60 usually comprises two outer grilles 66, 67 fitted to inlet and outlet openings, respectively, of drafts. The grille of outlet opening 67, that is located in front of portion 16 or of portion 18 is conveniently positioned, whereby to direct the draft upwardly and thus to prevent any trouble in the room to be conditioned. Fitted inside of said grille, fragmentarily shown at 68, at the level of inlet and outlet zones, respectively, there is provided a suitable filter 69 for example of fabric, felt or the like, spanning over both zones, to prevent a release of dust possibly collected in the course of a preceding operation of air conditioner, in its reversed position.

The component 61 is preferably formed with a single circular opening 62, that is connected by a nonsymmetrical coneshaped tubular fitting 70 with the related side of air conditioner, and is parted by a diaphragm 71 into its inlet and outlet sections. The use of a single opening is obviously advantageous from the installation viewpoint. In fact, when recourse is made to separate inlet and outlet openings, conditions of precise mutual spacing and positioning of the openings, to be formed in the window pane or panes 63, are to be strictly observed, while with a single opening such requirements can be obviated.

On the other side, short-circuiting problems would theoretically arise with a single opening even if properly parted by the diaphragm 7]. Otherwise stated, it might easily happen that at least a part of the (heated or cooled) outflowing air, be immediately sucked again into the air conditioner. And, as it can be readily appreciated, such danger may exist even on the side directed toward the conditioned room, owing to substantial coplanarity of both grilles 66,67 with which the inlet and outlet passages are fitted.

According to an important feature of the invention, the above danger is prevented by taking advantage of the already stated sharp difference in the speeds of incoming and outcoming air threads, and by subdividing the opening 62 and the inner front grillage of air conditioner by means of diaphragm 71 and of component 68, respectively, into inlet ports 72 and outlet ports 73, and into inlet grilled passages 66 and outlet grilled passages 67, respectively, in such a manner that the free area of passage of inlet ports be at least twice the amount of that of outlet ports, whereby to obtain that the speed of outflowing air threads be at least twice of that of inflowing air threads,

Actually and still taking advantage of the increment in the air speed as caused by the inherent features of previously described wheels, the outwardly directed outlet port 73 is dimensioned in such a manner that the speed of outflowing air be at least of 4-6 m/sec.

By such high speed of outflowing air, a compact blast of air is formed, which is dispersed into the atmosphere far beyond the zone wherein the outer air is perturbated by the sucking action exerted through the inlet port 72.

There actually occurs that no outwardly blasted air can be mixed into the air that is drawn through the inlet port 72 owing to kinetic energy ensured by the dimensioning of port 62. Also on the side directed toward the room to be conditioned, the prevention of short-circuiting phenomena is ensured by the far away sending of outflowing blast.

Obviously, the air conditioner is completed by suitable feeding, control and other means which are per se already known, whereby they have been neither described, nor shown. In particular, the air conditioner is fitted with suitable switches, thermostats and the like, which controls are preferably positioned on the top side of conditioner casing, in order to allow an easy accessibility thereto in either positions that can be taken by the reversible air conditioner.

In addition, and as diagrammatically shown in FIG. 2, the air conditioner can be fitted with valve means 80, 81, that can be controlled from the outside, as well as with passages 82, 83 respectively, whereby to bring the high pressure on delivery side of either warm and cold zones into communication with the low pressure or sucking side or the other zone or section, being thereby possible to ensure a supply of fresh air from the outside, or a discharge of stagnant air into the outside, being in the former case the inflowing air previously conditioned (i.e., cooled or heated).

In the actual manufacture of the improved air-conditioners according to the invention, recourse may be made to components and devices which are individually known and available on market, in particular as regard of compressor sets and the auxiliary feeding and control means. As combined axialradial flow fans 38, 40, recourse may be made to those produced by the Firm Torrington (HE Series) which show, within limits of sufficient practical approximation, all previously stated features, thus allowing to obtain, at least partly, the also previously stated advantages.

At any rate, various changes may be made in said air conditioners without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. An air conditioner apparatus, particularly of the reversible type for the air-conditioning of a single room or a small group of rooms, comprising a casing having two substantially parallel faces; an evaporator contained in said casing adjoining one of said faces; a condenser unit contained in said casing adjoining the other of said faces; passage means associated with said units for the intake of air from and the expulsion of air to the outside of said casing; a partition wall dividing said easing into two sections; and two rotary fans fitted back to back on either side of said partition wall and adjacent to one or the other of said faces respectively, both said fans being of the axial-tangential flow type having a plurality of curved blades having an intake portion of helical configuration screwly acting on the in-flowing air; an outlet portion tangentially acting on the air, and intermediate portion progressively evolving from helical to radial, said blades forming channels therebetween wherein the flow is progressively deviated from axial to radial while being acted upon said blades.

2. An improved air conditioner according to claim 1, comprising fans formed with a recess on their backs, and keyed on either ends of the shaft of a motor that is fitted in said partition wall and extending in either sections and into said fan recesses, the sum of axial dimensions of said fans and of said motor being smaller than the distance between the planes defined by the fan inlets.

3. An improved air conditioner according to claim 1, wherein the diameter of axial circular fan inlet portion is smaller than the diameter of tangential outlet portion thereof.

4. An improved air conditioner according to claim 1, wherein the fans comprise paddles having leading edges, the incidence of which gradually varies in reversed proportion to radial distance from the fan, whereby to form on the inlet side a spiral having a substantially constant pitch.

5. An improved air conditioner according to claim I, wherein a scroll conveyor, circumscribing the related fan wheel is provided in both warm and cold sections, leading said scroll, through a plane essentially tangential to same wheel into a space comprising a baffle plate, by which the air blast, coming from said scroll, is deflected toward the adjacent face of the conditioner.

6, An improved air conditioner according to claim 1, comprising components including tubular fittings and grilles and designed to be indifferently connected with said opposite major faces and formed with separate openings, positioned to juxtapose on the inlet and outlet passages for the air flows provided in either warm and cold sections.

7. The improved air conditioner according to claim 6, wherein each one of said components is formed with inlet and outlet ports for the air flows, being the passage sectional area of inlet port twice as great than that of outlet port, whereby to impart to outflowing air flow a speed at least twice as great that ofair flow sucked into the conditioner,

8. The improved air conditioner according to claim 6, comprising a component indifferently connectable to either major faces of the air conditioner casing and designed to fit into a single opening formed on a partition by which the room to be conditioned is separed from the external, said component comprising an essentially rectangular frame, adapted to match with the contour of either said major faces; an inlet port adapted to be engaged with said opening in said partition, a middle portion by which said rectangular frame is connected with said port, and an inner partition wall that extends from a line crossing said frame, in coincidence with the separation line between the air inlet and outlet ports formed on either said casing faces, to a line by which said opening is subdivided into two inlet and outlet ports, having the inlet port a passage area twice as great that of outlet port.

9. The improved air conditioner according to claim 8, wherein said opening is circular-shaped and wherein said partition wall forms a chord, the area of surface circumscribed by said contour being subdivided by said chord into two portions, one ofwhich is approximately twice as great than the other.

10. The improved air conditioner according to claim 7, wherein the component designed to cover the inwardly directed casing face is formed with essentially coplanar inlet and outlet openings, lying on a plane essentially parallel to heat exchanger (evaporator or condenser) adjacent to the major face of air conditioner casing with which said component is associated, an air-pervious filtering layer being provided to span over both inlet and outlet openings, through which the air is sucked from and delivered back, respectively, into the conditioned room,

I I. An improved air conditioner according to claim 1, comprising passages and operator controlled valve means, by which a space upstream of fan of cold section can be selectively and alternately put in communication with a space downstream of fan of warm section, and respectively a space upstream of fan of warm section can be put in communication with a space downstream of fan of cold section for controlledly providing the intake of air from the outside and the delivery thereof, after having been heated (or cooled) into a conditioned room. 

1. An air conditioner apparatus, particularly of the reversible type for the air-conditioning of a single room or a small group of rooms, comprising a casing having two substantially parallel faces; an evaporator contained in said casing adjoining one of said faces; a condenser unit contained in said casing adjoining the other of said faces; passage means associated with said units for the intake of air from and the expulsion of air to the outside of said casing; a partition wall dividing said casing into two sections; and two rotary fans fitted back to back on either side of said partition wall and adjacent to one or the other of said faces respectively, both said fans being of the axial-tangential flow type having a plurality of curved blades having an intake portion of helical configuration screwly acting on the in-flowing air; an outlet portion tangentially acting on the air, and intermediate portion progressively evolving from helical to radial, said blades forming channels therebetween wherein the flow is progressively deviated from axial to radial while being acted upon said blades.
 2. An improved air conditioner according to claim 1, comprising fans formed with a recess on their backs, and keyed on either ends of the shaft of a motor that is fitted in said partition wall and extending in either sections and into said fan recesses, the sum of axial dimensions of said fans and of said motor being smaller than the distance between the planes defined by the fan inlets.
 3. An improved air conditioner according to claim 1, wherein the diameter of axial circular fan inlet portion is smaller than the diameter of tangential outlet portion thereof.
 4. An improved air conditioner according to claim 1, wherein the fans comprise paddles having leading edges, the incidence of which gradually varies in reversed proportion to radial distance from the fan, whereby to form on the inlet side a spiral having a substantially constant pitch.
 5. An improved air conditioner according to claim 1, wherein a scroll conveyor, circumscribing the related fan wheel is provided in both warm and cold sections, leading said scroll, through a plane essentially tangential to same wheel into a space comprising a baffle plate, by which the air blast, coming from said scroll, is deflected toward the adjacent face of the conditioner.
 6. An improved air conditioner according to claim 1, comprising components including tubular fittings and grilles And designed to be indifferently connected with said opposite major faces and formed with separate openings, positioned to juxtapose on the inlet and outlet passages for the air flows provided in either warm and cold sections.
 7. The improved air conditioner according to claim 6, wherein each one of said components is formed with inlet and outlet ports for the air flows, being the passage sectional area of inlet port twice as great than that of outlet port, whereby to impart to outflowing air flow a speed at least twice as great that of air flow sucked into the conditioner.
 8. The improved air conditioner according to claim 6, comprising a component indifferently connectable to either major faces of the air conditioner casing and designed to fit into a single opening formed on a partition by which the room to be conditioned is separed from the external, said component comprising an essentially rectangular frame, adapted to match with the contour of either said major faces; an inlet port adapted to be engaged with said opening in said partition, a middle portion by which said rectangular frame is connected with said port, and an inner partition wall that extends from a line crossing said frame, in coincidence with the separation line between the air inlet and outlet ports formed on either said casing faces, to a line by which said opening is subdivided into two inlet and outlet ports, having the inlet port a passage area twice as great that of outlet port.
 9. The improved air conditioner according to claim 8, wherein said opening is circular-shaped and wherein said partition wall forms a chord, the area of surface circumscribed by said contour being subdivided by said chord into two portions, one of which is approximately twice as great than the other.
 10. The improved air conditioner according to claim 7, wherein the component designed to cover the inwardly directed casing face is formed with essentially coplanar inlet and outlet openings, lying on a plane essentially parallel to heat exchanger (evaporator or condenser) adjacent to the major face of air conditioner casing with which said component is associated, an air-pervious filtering layer being provided to span over both inlet and outlet openings, through which the air is sucked from and delivered back, respectively, into the conditioned room.
 11. An improved air conditioner according to claim 1, comprising passages and operator controlled valve means, by which a space upstream of fan of cold section can be selectively and alternately put in communication with a space downstream of fan of warm section, and respectively a space upstream of fan of warm section can be put in communication with a space downstream of fan of cold section for controlledly providing the intake of air from the outside and the delivery thereof, after having been heated (or cooled) into a conditioned room. 